Gyratory vibration screen apparatus



July 26, 1949.

Filed Dec. ll, 1944 si J. GILSON GYRATORY VIIBRATION SCREEN APPARATUS 6 Sheets-Sheet 1 July 25,' l949- s. J. GlLsoN A 2,477,123

GYRATORY VIBRATON SCREEN APPARATUS Filed Dec. l1, 1944 6 Sheets-Sheet 2 July 26 1949- s. .1.v GlLsoN 2,477,123

GYRATORY VIBRATION SCREEN APYPARATUS FledDec. ll, 1944 6 Sheets-Sheet' misrx munmm July 26, 1949. s. J. GlLsoN- GYRATORY VIBRATION SCREEN APPARATUS 6 Sheets-Sheet 5 Filed Dec. 11,l 1944 figli- 3 5 INVENTOR. 8?/

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Patented July ze, 1949 UNITE-D STATE-s PATENT oFFicE -oYRAToRY vmRAfrioN soREEN APPARATUS l'st-th i. Giison, c 1eve1ana o 1iit,assigiititt ninth & INe'eb Company, Cl'veland, Ohio, a partner- 'ship Application December 11, 1944, Serial o.'567i593 8 claims. (c1. zt-l-fze) t marily involve a construction including a spporting 'or dead fra'rne and a live or vibrating screen unit comprising 'one or .more superposed screen frames or sections, 'said unit carried by the supporting frame and vibrated by suitable power mechanism connected therewith. Screens of the Y type of my invention as designed for certain uses employ 'dust covers above the screen unit, beneath the unit, and leading from the discharge 'end of the 'screen or screens of the unit- One of the problems of the construction of Y vibrating screens of the type's heretofore proposed resides in the dimculty of removing and replacing thescreen or screens of the screen unit, for necessarily these screens are 'subjected to considerable wear under practical conditions of service.

It has therefore been one 'of the primary objects of my present invention to 'so design my vibrating screen as to enable 'the quick 'and ready removal of the screen members, and their replacement. While 'heretofore in many instances the screen removal and replacement operations have necessitated the detachment of the dust covers when they are employed, my lpresent improvements eliminate the necessity of such dust cover detachment by provisions for displacing and emplacing the screen members laterally from the vibrating screen unit in a manner novel as compared with provisions heretofore employed 'for the purpose.v Moreover, with the foregoing objective in mind, the supporting frame for the vibrating screen unit in my invention has been constructed with a view to facilitating the foregoing displacing and replacing operations for the screen members by provisions of clearance spaces at the sides of said supporting frame.

Incidental to the foregoing phase of my improvements, I employ a screen unit which comprises a novel construction of screen frames or sections united by special fastening means, 'enabling the separation of the screen unit frames or sections in a relatively short time for screen removal purposes and the restoration of the said frame members or sections to their original positions properly holding the screen members in piace, in a correspondingly short period of time.

The fastening means of my invention, usedfor holding the screen sections' or frame members of the screen unit together arelocated a novel mannerat the opposite sides of said unit, readily accessible from opposite sides oi the sifrtlng tiene and 'said unit, 'so that they may here: moved 'and rep af'c` without difficulty and with;v qut disturbing in any way'the attachment of the ust covers that may be employed in poniiiiietitii 'with th deleting 'stijgen of iiiy im/eti; tion, 'and dependent upon particular conditions of use. A

By reason of the foregoing provisions, the loperations "c'f idetaohing' a worn out screenn'or screens rom one r'fmore screen holding frames or members of 'the screen 'nnift are rendered very simple, quick of performance, `and, 'the replace'- mnt'thereof 'wir 'o i' new screen members is correspondi" 'erfeictet bythe maniplation of a minimum nmber of ias'tening devices with asimilar re'dction in the 'time factor, something highly essential for the piirpses of "screen de"- vic'e's of the "class 'to which my improvements appli' t i i Vsti-11 another obiettive inthe development off the improvements helb b the 'provision of a vibrating screen unit which is dissed vin a horizontal position, with the -m'e'sh'ed screens simil-arly s'o disposed, and'which is subjected to a novel vibrating action in a direction slantin'g' upwardly toward the discharge end of the screen unit such vaction maintaining 'the mesh open# ings `of the screen members 'in positions 'siich that their sizing o r grading functioning is in no way interfered with; the said peculiar vibrating "a'c: tion -of 1the screen unit at the same time compelling a traveling movement of the material be: ing screened toward the discharge 'end vof the unit by the multitudinous vibrating impulses imparted to the screen unit during the operation thereof. The advantage in employing a screen unit which is generally horizontally disposed will be more apparent upon reference to the following detail description, it being notable, how` ever, ,that 'when vibrating screen units aredisposed in generally .inclined or slanting positions; the eiiiciency of theseparating Aor grading action of the screen members themselves is reduced throgh the inclination of the mesh openings oef said screen members.

Having `in mind the foregoing outline of the general operating or vibrating movement of the screen my invention comprises novel instru-A mentalites in the forni of spporting spring or resilient members providing a unique spring suspension for the vibrating screen unit by reason of whioh, ndr the operation of the ti'rating iiittiv fortes, the peculiar movement of the screen members is ei'ected in an upward inclined direction toward the discharge end of the iin'i'tz as above referred to,

Si 'sidiary to the phase of my invention involi/'ing the special provisions pertaining to the removaibility and replaceablility of the screen tri siifig ti resilient suspension means sections of the screen unit to aiford the adVa-ntageous lateral removal and replacement of screen Y parts or members, the provisions of the peculiar fastening means between the said sections of theV screen unit, according to my present improvements, permit such removal and replacement operations to be performed independently in reference to upper and lower screen members, or substantially at the same time if desired, all with a reduced time factor for such operations as compared with corresponding ,operations in prior art screen devices of the type of my invention.

My present improvements involve furthermore, novel tension and clamping devices for tensioning and clamping the screen members in position upon the screen unit, clamping devices that are quickly and readily operable from a side of the apparatus or screening device so` that againthere is no necessity for removing andreplacing dust covers in order to handle the screen members in the manner referred to.

Myinvention further involves driving devices associated with the dead or supporting frame of the vibrating screen and with the vibrating screen unit, power driven by any suitable power mechanism, and which drive devices may be reversed so as to carry the drive to rthe screen unit from either side of the screen, this being advantageous, having in view the necessity for locating the screen device in diiferent places in a factory or builidng.

In the drawings:

Figure 1 is a side elevation of a vibrating screen embodying the novel features of my invention.

Figure 2 is an end view of the screen, showing that end at which are located the driving instrumentalities for vibrating the screen unit.

Figure 3 is a top plan view of the screen, partially broken away near one end to condense the view, and partially showing the screen cloth of the upper screen members.

Figure 4 is a longitudinal sectional view of the screen, bringing out more clearly the superposed screen members of screen cloth and the mounting means between the screen unit and the supporting or dead frame; also certain of the clamping and tensioning means for the screen members, the view being taken on line 4-4 of Figure 3.

Figure 5 is a transverse sectional view taken about on the line 5-5 of Figure 3. l

Figure 6 is a transverse sectional view of the screen unit alone, showing somewhat more clearly the operating means for the intermediate clamp-- ing bars coacting with the adjacent ends of the upper screen members.

Figure 7 is a detail View, enlarged, showing a corner portion of the screen unit, bringing out more clearly the arrangement of the corner hanger bolts and the attaching means for'the upper and lower screen members.v l

K Figure 8 is a plan view broken away at the middle, showing one of the upper screen members of the screen unit. l

Figure 9 is a view similar to Figure 8, but illustrating the lower screen member of the screen unit, the middle portion of the screen broken away in the illustration.

Figure 10 is a fragmentary plan view showing 4 a modified form of upper screen member attaching instrumentalities.

Figure 11 is a detail sectional View taken about on the line lI-ll of Figure 10.

Figure 12 is a side view showing more clearly the screen member attaching or clamping means illustrated in Figures 10, and 11, the view looking toward the screen unit in the direction of the arrows I2-I2 of Figure 10.

' Figure 13 is a somewhat diagrammatic view illustrating my vibrating screen apparatus with cover means therefor, and dust covers leading from the sections of the screen unit, showing somewhat more clearly the side clearances enabling the removal of the screen members without aifecting the dust covering or enclosing elements.

Figure 14 is a perspective view of one of the upper screen clamp plates, the lower of two, as used in the modification of Figures 10 to 12.

Figure i5 is a fragmentary view in section of the screen unit sections clamped together, showing the structure at one end of the unit.

Figure 16 is a view similar to Figure 15 but showing the sections as when separated for removal of the screens, and disclosing the tension means for longitudinally pulling the lower screen taut, as vfound at the opposite end of the unit.

Figure 17 is a sectional view, broken away, of one of the two like bearing structures between the sides of the middle section of the screen unit, and the vibrating shaft and long spring supports for the unit, showing details not elsewhere illustrated.

Figure 18 is a fragmentary view of one of the vibrating shaftpulleys showing the structure by which it interlocks with said shaft.

For the purposes of the following description, I shall refer to the main supporting frame of my screen as the supporting or dead frame, the vibrating screen proper as the screen unit comprising top, middle, and bottom frame sections or members, and the screen cloth parts as screen members, the preferred construction of my inven- 45 tion including three upper screen members in the same plane and a lower single or continuous screen member extending from end to end of the apparatus. However, it is understood that th-e upper screen members might be consolidated into or substituted by a single screen member and the lower screen member could be made in sections if desired, within the purview of my invention.

Referring to the drawings, and designating the various parts of my construction, the base supporting or dead frame is composed of lower longitudinal members or angles I, transverse members or angles 2 connecting the members l at the ends or corners of the frame. Upstanding from the parts l and 2 at the corners where they join are the corner posts 3 made from angles or any suitable metal shapes, preferably. At the sides of the screen, by which term I designate the entire screening apparatus, are the longitudinal bars 4 preferably made from channels. These bars 4 are part of the supporting frame and are spaced above the longitudinal members i of the supporting frame and are attached at their ends by bolts or rivetsl 5 to the angle posts or uprights 3. At one end of the supporting frame the members 3 are connected by a transverse bar 6, seen best in Figures 2 and 3, this member rigidifying the supporting frame structure and carrying certain parts of the driving mechanism.

In Figure 2 the driving means illustrated comtom and top surfaces, respectively, of the sides ci the members I1 and I6; Therefore, obviously, the tightening of the bolts 32 and 39, bringing the screen sections I'I and IB together, will by impingernent clamp the plates 42 in position. Before final tightening adjustment of the bolts 32 and 39, vertical wedges 44, see Figure 6, may be driven through the slots in the extensions 43 of the plates 42, and, binding against the outer' surfaces of the sides of the section I1, are adapted to place the screen members 4I]v under lateral tension. 'i

The foregoing disposes of the tensioning or fastening or the screen members 48 laterally of the screen unit parts I1` and I6.

The adjacent edges of the Screen members 48, as seen in Figures 3 and'fi, are adapted to be tightly clamped by special clamping mechanism operable from a side of the screening apparatus. Figures and 6 show the clamping mechanism as well as Figure 4.

The clamping means, as to the parts upon the top section I1, includes the cross beams 45 extending transversely between the sides of the member I'I, and rigidly attached thereto. Depending struts 43 on the beams 45 carry T-shaped upper clamp plates 41. The middle webs of these clamp plates 41 project downwardly into slots of transverse movable beams 48 in vertical line with the beams 45 and beneath the clamp plates 41. The movable beams 48 are supported for vertical bodily movement between the sides of the section i8 and are movably carried on sleeves 49 at the upper ends of spaced levers 58, two pairs of which are located between the sides ofthe section I6 for each of the beams'48. Cross parts or beams 5I, each comprising a metal plate member, span the space between and are secured to the sides of the mid section I6, and the lower ends of the levers 58 are pivotally secured at 52 to the adjacent beam 5I. Each set or pair of leversV 58 is virtually a lifting jack.

Obviously, by moving the` upper ends of the pairs of levers 58 beneath beam 48 toward each other, the movable clamp beams 48 will be shifted upwardly 'to clamp against the'edges of the screen members 48 received between the stationary T- members 41 and Said beams 48, see Figure 4. The movement of the'levers 58 is adapted to be effected by means operable from a side of the apparatus as seen in Figure (i and including operating members in the form of Socket headed screws 53 having threaded portions 54, one screw 53 being provided for the two sets of levers 58, or the two jacks, for each beam 48. The threaded portion 54 of each screw 53 is threadedly connected near the right end of the screw with the sleeve 49 on the right jack or pair of levers 58, as seen in Figure 6. Said screw near its outer end is movably connected with the-left sleeve 49 between two collars 51 xed against sliding and mounted on the screw 54; A turning of each screw 53 in one direction will bring the upper ends of the jacks 58 toward each other ,for raising the sleeves 49 and movable beam 48, and an opposite direction turning of the screw 53 will separate the upper end of the jacks 58 for lowering of the beam 48. In this manner the clamping and unclamping action of the beam or beams 48 is eifectively controlled in relation to the transverse end edges of the screen members 48, and the parts 478 and 41 clampingly-maintain tension on the screen members 48 in a lengthwise direction of the entire vibrating screen unit. Later I shall describe how the jacks 58` coact for action on the clamp plates or beams 5I to assist in holding the lower screen 62 taut.

Proper separation oi the sections I1' and I6 of the screen unit, as later described, after removal ci the wedges 44 and bolts 39, enables a displacement or removal of the screen members 48 laterally and outwardly from the space between the parts I1 and I8.

At its end portions the upper section I1 of the screen unit is equipped with angle clamp members 58, one connected by struts 59 with a superposed cross beam 68,'and each angle plate 58 constitutes a clamping member, one at each end of the unit section I1, adapted to seat upon and clamp the screen cloth material at the adjacent transverse edge of each of the end screen members 48. In other words, the plates 58 might be characterized as half-T plates or single flange clamp plates as distinguished from the double or T-clamp plates 41. The plates 58 work in conjunction with the end members 6I of the frame of the unit section I6.

I now proceed to a description of the lower screen member. As previously indicated, this member is preferably continuous from end to end of the vibratory` screen unit, though, if desired, it could be made of sections in a manner similarly to the members 48 and held in place by similar clamping means.

It is contemplated that the lower screen member shall be mounted between the sections It and I8 of the vibratory screen unit, and it is likewise displaceable laterally from either of opposite sides or" the apparatus by reason of the structure of the supporting or dead frame which provides the necessary clearance spaces through which the members 48, or the lower screen member 62, is removed and replaced, see Figures 4, 5 and 9.

The cross members or beams 5I previously referred to as -being carried by the middle section I6 of the screen unit form upper bearing surfaces for the screen member 52 at points intermediate its ends as seen in Figures 4 and 5 and beneath the members 5I and providing lower bearing surfaces for such portions of the screen member B2 are the cross beams 63 carried by or attached at the ends thereof to the sides of the member I8. Therefore, the screen member 62 is thus supported and clamped intermediate its ends between the members 5I and 63. The ends of the lower live frame members I S are formed, as best seen in Figures 4 and 7, with recesses 84 adapted to receive the end plates 62a of the screen member 52 and when the sections I6 and I8 are firmly clamped together, one end of section I6 bearing down upon the angle plate `65 secured thereto clamps the adjacent plate 62a at one end of the screen member 62 into the groove 64 of the adjacent rigid crossy member of the frame section IES. At the opposite end of the screen member 82 the cross or end member of the frame section I8 designated |80, is movable slightly in a longitudinal direction as seen best in Figure 1, sliding on an angle plate 66 and moving in recesses in the ends of the sides of the section I8. This movable cross member Ia of the section I8 is therefore capable of longitudinal sliding in relation to the body of the section I8, and there are provided screw bolts `S1 suitably headed for wrench application purposes adjustable and cooperating with the lower hanger brackets 34 so that upon screwing the bolts 'S1 in opposite directions, opposite movements may be imparted to the beam Ia, which "closures in any Way whatsoever. screen members are removable and adapted to be 11 Vadapted to have bellows connection with a suitable hopper to which is supplied theA aggregates coming from the upper screen members 40; also the dust cover means 92 having bellows connectionwith another hopper to which the aggregates coming on" the lower screen member 62 will be delivered. This view simply typifies the manner in which the dust covers may be arranged permanently and nevertheless; permit of the removal of any one or more of the screen members without disturbance of the dust covers or en- To this end the replaced laterally of the screen unit from between the several sections I6, I1 and I8, as will be more fully set forth.

Y The general operation of screening apparatus of my invention involves the special unique actuatingimovements imparted to the screen unit by means of driving mechanism operated by a suitable motor not shown transferred to the driving shaft made up of the sections 8, l2, and I4, actuated by the pulley 1 on the shaft section 8. Driving action of the said sectional shaft is transferred, as previously set forth, by a pulley wheel v2li having the belt connection 21 with the pulley wheel 28 carried by the vibrating shaft 29.

The shaft 29 is driven at high speed and the operation of the screen unit in reference to the vibrating forces imparted thereto is substantially as follows:

In describing the operation` of this apparatus, it should be understood that the screen unit is elevated from its normal low position to its upper position on an inclined path and suddenly returned in the reverse direction to the lower position, during which rectilinear reciprocation the screen unit is maintained in a true horizontal position. These reciprocatory motions upwardly and downwardly in the inclined plane referred to take place at relatively high speed--in the order of 1000 reciprocations per minute. It is this sudden reciprocatory motion which imparts to the aggregates on the screen the jumping action that effects a travel of the aggregates continuously toward the discharge end of the lunit and incidental falling of these aggregates Vthrough the full effective area of the screen mesh. The operation of this screen unit in the manner above stated is caused by the action of the crank pins 'l0 at the ends of the shaft 29 upon Jthe longitudinal springs 68 through the full orbit of these pins of 360, in conjunction with the suspension of the unit upon the resilient flexible end members 'Il and the resilient intermediate members 16,V as well as the substantially vertical slightly laterally movable members 13 attached to the extreme ends of the longitudinal springs 68.

y More specifically setting forth this action and describing the operation of the parts on one .side of the apparatus, referring to Figure 1, for

example, the operation of the parts at the oppo- .site sides being identical, it is rst assumed that the crank pin is at the top of its orbit path with Vthe associated longitudinal spring 68 substantial- Vly straight and the vibratory screen unit at the lower position. As the crank pin 'l0 moves clockwise toward the position shown in dotted lines in Figure 1 of the drawings, it first bows the lonsition'latera-lly leftward. In the foregoing movement, the spring 68 is symmetrically distorted. This action, in which each half of the spring acts as a lever with the associated spring 'I6 acting as a fulcrum, raises the screen unit vertically through the lifting effect of the springs 68 on the substantially vertical exible members 13. As a result of this elevating motion, the screen unit is shifted to the right and upwardly by virtue of the iexing of the inclined end springs 1I toward a vertical position. In other words, the lifting effect on the vibratory screen unit exerted by the substantially vertical members 13 produces a rightward upward shifting of the upper ends of the inclined spring members 1l to cause the screen unit to move in the slantingly rightward upward path of reciprccation. This path in reality is a relatively large arc. This inclined movement upwardly with the screen unit in its horizontal position throughout, as stated above, takes place through the first movement of the crank pin from its top center to its lower center shown in Figure 1.

The return of the screen to its lower position by reciprocation in the reverse direction over said arc takes place incident to the movement of the crank pin 'l0 during the final half or 180 of its movement from the lowermost position of Figure 1 to its topmost position in the orbit, the various parts being thereby restored to the initial positions assumed thereby when the spring 68 issubstantially straight or with its central portion at the uppermost limit of its movement. That is to say, as the crank pin 'i0 rises, the spring 68 is shifted bodily toward the right, during the last quarter of turn accompanied by the movement of the spring members 'I6 to their original inclined position from which the described operation commenced, the spring members 13 moving rightward toward their vertical positions. As this action is produced. the screen unit is caused to move downwardly, which downward movement is accompanied by the shifting of the end inclined springs 'H toward their initial inclined position to the left. During the complete cycle of movement of the parts as above described, the top point of the member 1B and the corresponding Vpoint of the top of the end connecting member 'Il move toward and from each other, speaking with reference to each pair of said members at each end of the spring 68. It is this compound action of the suspension members which elects the travel of the screen unit in the reverse or downward path of reciprocation on the inclined plane.

.from the brackets 34, and the coiled springs 35 by their expanding eiect will raise the section I'I of the screen unit from the section i6. The several screen members 40 may be displaced latferally from the side of the screen unit where the bolts have been entirely removed under the above conditions. If only one of the screen members 40 is to be removed, it is only necessary to displace completely the two bolts 39 at the end of this screen member at the side of the unit from which the screen member-iste be displaced, for obvious reasons. After a screen member 4e' has been removed and a fresh screen member replaced in its stead, the displaced boltsv39 will be replaced and all the bolts 3S screwed down again to clamp the section I 'I of the unit against the section I6 of the unit; likewise the corner hanger bolts 32 will be tightened down again on the corner brack etsv30. 'Y

Now if the lower screen member 62 is to be displaced, the various lower bolts 4i at 4opposite sides of the screen unit will 'be unscrewed. The bolts 4| at one side of the screen unit, at which side the screen member 62 is to be displaced or removed, willthen'be entirely removed from the unit. Thereafter, the corner hanger bolts 32 will be unscrewed and this action 'will Venable the gravitative lowering of the section IB of the screen unit to enable it to separate from the section I'1 in a spacing manner andL free the screen 62 for removal operation. Of course, before removal of the screen 52 the tension bolts'l will have to be operated to release the pull on the tension beam 18a so as to facilitate the removal -of the screen 62.

The operations above referred to are simply reversed after the screen 62 has been removed and afresh screen member is to be emplaced in its stead. i

Now in lthe above screen member handling operations involving removal and replacement of said members, it will be obvious that a relatively small number of bolts have to be removed and re-y placed, and simple other .detaching operations performed. Moreover, there is no necessity for disturbing any dust covers attached to the screen apparatus because the screen members are removed and replaced from the sides of the apparatus and not `from above or below. Those of the clamping devices used for the screen members are of course operated to release the screen members when they are to be removed and to reclamp the fresh screen members replaced, in a manner obvious fromv the foregoing general .presentation of these details of the invention. v v

Because of the simplicity of the screen member removal and replacement operations, a material saving in time for effecting these operations is obtained, this being a veryim'portant desideratum` One purpose in providing the struts or spaced members e6 and 59 is to permit flow of the screened materials along the upper screen toward the delivery end of the upper screen (the right end as seen in Figures l and e). .Y As 'seen in Figure 3 the long springs t8 are formed near opposite ends with openings 16a, or bolts 7Gb may be adjusted for adj-ustably securingv the upper ends of the flexible members 16. Likewise, 'the brackets 'il' may be adjustable on members Zi for a like adjustment of the lower ends of the springs "it, vopenings 'itc at intervals in the members l being provided for adjustment of the fastenings i8 (see Figure 1).

Adjustment or the springs closer than 'in Figures l and 3, by the above means 16o and i8 increases the severity of the vibration of the screen unit; opposite separating adjustment lessens the severity of the said unit vibration.

lntermediate its end portions and transversely of 'the screen unit, the lower long screen B2 is clamped in each of two places (see Figures 4 and 6) by the beam member that includes the previously described plate 5l, struts 51a, and alower cross `plate .511). The plate member 5l is provided with 'stiifeni'ng flanges 51C to which the jacks are pivoted. But intermediate the flanges 5|c the'parts 5I and 5 lb of the beam member can flex or yield. Therefore, the action of the jacks 50 is not only that ofraising the lclamp beams 48, but also that ofbearing'down equally to effect clamping action of the beams 5I, '5|a, 5lb, upon the lower screen t2 thereby to hold the latter tensioned transversely at the two places where the said last beams are located. Y

Thus the jacks 50 have a double clamping function in coacting with the upper screen members MJ, and the lower screen member E2.

Since the construction of the shaft 29 and cone nections by the bearings 69 to the long springs 58 is peculiar and cannotbe completely illustrated in'Figuro 5, reference is made to Figures 17 and lS'for anunderstanding thereof. In Figure 1'? shaft E9 is partially shown Within its housing 'iii that is secured at its ends to the inner faces of the sides of the section I6 of the screen unit. Said shaft passes throirrh said sides, each of which .supports bearings S5 iil the housing 'I9 for receiving the shaft endadjacent. The eccentric member :or cranklpin 'i0 is integral with each shaft end as seen, and each pulley 2a is formed as shown in Figure 18 with a recess 9S and opening el. The recessreceives the end of the shaft 2e at its .juncture with the crank pin 10. The pin 'lo passes through the opening 91 which is eccentric tothe. recess 96. This `construction inter locks-"the pulley 2c to the shaft preventing rotation of the pulley relatively to the shaft so no key or spline is required.. f

.The .crank pin .10. projects outward fromV the pulley 2; to enter thebearlingmember or pillow block Eil of the adjacent coacting .spring 68 (see Figures l and 4), and is'provided with the reduced threaded end 'illu-that receives nut 93. The nut EIB holds in place the inner race for the ball bearings 9s between the pin'l and the bear'- ing member orA block Se secured to spring 58. The outer race of the bearings 99 is held in place by the inner race, as is obvious. A closing cap MJD is used toclose `the bearing means and may be frictionally or otherwise attached to the member SS. The construction of Figures 17 and 18 is in duplicate for the opposite sides of section i5 of the screen unit.

It will be noted from the foregoing disclosure of my invention that my screen unit is flat or horizontal in its general position during vibration operatiomvwhich permitsperfect sizing of the material and gravitation of the material at a right angle to the moving screen members and material thereon. The screen unit is designed to havel a conveying action of the material over its surface which is at. acontrolled speed.

By reason of. the construction of the screen unit in three Sections, top, middle, and `bottom frames, virtually speaking, there are afforded quick change advantages for the screen members independently of cach other., `and also they can all be removed and replaced at the same time relatively quickly, to afford material .saving in time and labor, as previously indicated. Necessarily, this advantage increases the operative productive capacity of the screenunit.

The full floating driven -shaft and housing means are carried in the. vibrating unit coin'- pletely and employed solely to function to set up the vibrating impulses in the specially designed spring suspension that .supports ,the vibrating unit. Under these conditions, it requires very littlejpower to drive the shaft 29 with its eccentricendmembers -or cranks, thereby ,reducing the' shock throughout the entire screen, affording an economy in the maintenance cost of the apparatus.

My improved arrangement and design of the spring suspension means for the vibrating screen and actuating means, therefore, will impart a positive action to the vibrating screen unit with every revolution of the shaft 29, effecting said vibration at a substantially 60 angle to the flat screen surfaces of the screen members.

All fastening means for the sections of the screen unit are accessible from the outside as well as the jacks or clamping devices that are manipulated for clamping inner edges of certain screen members or tensioning the screen members at various points. All stretching action of the screen members is effected also from the outside f the unit.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States, is-

1. In vibrating screen apparatus of the class described, in combination, a base or supporting frame, a vibratory screen unit mounted thereon and comprising screen members carried by said unit, a floating mounting between the screen unit and the supporting frame including a transverse driven shaft connected to the screen unit at approximately the middle portion thereof, a pair of longitudinal springs one at each side of the screen unit, eccentric driving connections at the ends of the driven shaft connecting with said springs for effecting longitudinal back and forth movement of the longitudinal springs and upward and downward movement of the middle portions of said springs, substantially vertical members depending from the ends of the longitudinal springs and having connection with the supporting frame near the ends of the latter, and members connecting the longitudinal springs adjacent to the ends thereof with the supporting frame, said last members being normally inclined in one direction.

2. A screen apparatus as claimed in claim 1, combined with members movably connecting the ends of the supporting frame and the ends of the screen unit.

3. A screen apparatus as claimed in claim 1, combined with members movably connecting the ends of the supporting frame and the ends of the screen unit, the last mentioned members having a normal inclination opposite that of the inclined members which connect the longitudinal springs near the ends thereof with the support-ing frame.

4. In screening apparatus of the class described, the combination of a supporting frame; a vibratory screen unit associated with said frame; means forV suspending the screen unit on said frame including a longitudinally extending flexible member at each side of the screen unit, shiftable elements connecting the ilexible members to the supporting frame and to the screen unit maintaining the screen unit in horizontal position, said elements being disposed in such positions to impart movements to the screen unit vertically, and actuating means carried by said screen unit and operably connected to the longitudinally extending ilexible members to effect exure and longitudinal movement of the last mentioned members and reciprocatory movements of the screen unit in an inclined plane while said unit is maintained in a horizontal position.

5. In vibrating screen apparatus, in combination, a screen unit, screen members mounted thereon, a supporting dead frame` for carrying the screen unit during its vibrating operation. means for eiecting vibratory operation of the screen unit comprising an actuating shaft mounted on the screen unit, long springs at opposite sides of the screen unit, eccentric members on said shaft having bearing connections with said long spring members intermediate the ends of the latter for vibrating said spring members upwardly and downwardly and longitudinally, rst members at the ends of the long spring members connecting the same with the screen unit, second members connecting the long spring members with the supporting dead frame, and other members connecting the screen unit with the supporting dead frame, said spring members, rst and second members, and other members referred to operating to control free floating movement of the screen unit and to maintain said unit horizontal during vibration thereof.

6. A vibrating screen apparatus as claimed in claim 5, wherein the second members mentioned are inclined toward one end of the long springs to which they are connected.

7. A vibrating screen apparatus as claimed in claim 5, wherein the second members mentioned are inclined toward one end of the long springs to which they are connected, and in which the other members referred to as connecting the screen unit with the supporting dead frame are inclined oppositely to the direction of inclination of said second members.

8. A vibrating screen apparatus as claimed in claim 5, wherein the second members mentioned are inclined toward one .end of the long springs to which they are connected, in which the other members referred to as connecting the screen unit with the supporting dead frame are inclined oppositely to the direction of inclination of said second members, and in which the rst members that connect the ends of the long spring members to the screen unit are normally vertically disposed and are movable longitudinally of the apparatus for permitting the longitudinal shifting or" said spring members.

SETI-I J. GILSON.

REFERENCES CITED The following references are of record in the iile of this patent:

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